Strain relief devices for cables for communications and data technology have been known in widely differing embodiments for a long time.
DE 40 09 297 C2 discloses an apparatus for attaching at least one cable to the racks or housings of telecommunications devices, having at least two toothed rods which are arranged on the rack part, in which case at least one cable is inserted between the toothed rods and can be secured by means of a spring element which can be clamped between the toothed rods.
DE 198 11 476 C1 discloses a cable clamp for making contact with the shield of cables when they are being fixed on a contact plate, comprising a web and two outer limbs which are connected to this web and are provided with cut-free lugs as holding elements for fixing the cable clamp on the contact plate, with the web being in the shape of a circular arc pointing outward in order to make contact with the cable shield, and being provided with web strips on the edges, pointing inward, for pressing into the cable shield, with the circular arc of the web being arranged symmetrically with respect to the cross section of the cable clamp, being matched to the external circumference of the cable to be connected, and, in terms of cross section, extending over only a portion of the length of the web.
The known strain relief devices have the disadvantage that the cable conductors are not aligned in a precisely defined manner with respect to the contacts of a plug connector which is to be connected to the cable. Particularly for very high transmission frequencies, this results in very large tolerances for crosstalk between adjacent conductor pairs and contact pairs.
DE 100 51 097, which has not yet been published, discloses a strain relief device for a plug connector for communications and data technology. The strain relief device in this case comprises an essentially U-shaped base part for holding at least part of the plug connector and of a cable which can be connected to the plug connector, with the base part being formed with the first latching means, and closure means, with the closure means being formed with second latching means, which form a latching connection with the first latching means on the base part. The base part is formed, on the lower face of the limbs, with guides which point inward, run parallel, and run at right angles to a rear wall of the base part. In the upper region, on the inside of the limbs, the base part is formed with in each case one obliquely running guide edge. The obliquely running guide edges are in this case designed to be complimentary to the guide edge of a cable manager. When the base part is put onto the cable manager and a plug connector housing, the cable manager is moved in the direction of the plug connector housing, and latches with it. During this process, the cable conductors make contact with the electrical contacts in the plug connector housing. Furthermore, the base part has two jaw parts which can be bent together and are articulated in a sprung manner on a base which is arranged on the upper face of the guide edges. The jaw parts are in the form of steps on the sides. Four openings, in the form of elongated holes, are arranged on each of the two sides on the upper face of the base. In the internal region, the two jaw parts are formed with pyramid-like structures. A spring, which acts as a locking means, can then be inserted into the openings, and a rigid closure element can be latched on. The essentially U-shaped closure element is for this purpose formed on the insides with latching troughs, which latch in on the legs of the spring. The known strain relief device has the disadvantage that its design is mechanically relatively complex owing to the moving jaw parts, which means that it must be manufactured from plastic.